Type I Clathrates as Novel Silicon Anodes: An Electrochemical and Structural Investigation

Advanced Science

Ying Li¹  Rahul Raghavan¹  Nicholas A. Wagner¹  Stephen K. Davidowski⁴  Loïc Baggetto²  Ran Zhao⁴  Qian Cheng¹  Jeffery L. Yarger⁴  Gabriel M. Veith²  Carol Ellis-Terrell³  Michael A. Miller³  Kwai S. Chan³ 

[1] Materials Science and Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA;Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA;Department of Materials Engineering, Southwest Research Institute, San Antonio, TX, USA;Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, USA

关键词: anode;    Li‐ion battery;    silicon;    ternary type I clathrate;   

DOI  :  10.1002/advs.201500057

来源: Wiley

【 摘 要 】

Abstract

Silicon clathrates contain cage-like structures that can encapsulate various guest atoms or molecules. An electrochemical evaluation of type I silicon clathrates based on Ba₈Al_ySi_46−y as the anode material for lithium-ion batteries is presented here. Postcycling characterization with nuclear magnetic resonance and X-ray diffraction shows no discernible structural or volume changes even after electrochemical insertion of 44 Li (≈1 Li/Si) into the clathrate structure. The observed properties are in stark contrast with lithiation of other silicon anodes, which become amorphous and suffer from large volume changes. The electrochemical reactions are proposed to occur as single phase reactions at approximately 0.2 and 0.4 V versus Li/Li⁺ during lithiation and delithiation, respectively, distinct from diamond cubic or amorphous silicon anodes. Reversible capacities as high as 499 mAh g−¹ at a 5 mA g⁻¹ rate were observed for silicon clathrate with composition Ba₈Al_8.54Si_37.46, corresponding to ≈1.18 Li/Si. These results show that silicon clathrates could be promising durable anodes for lithium-ion batteries.

【 授权许可】

CC BY   
© 2015 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.